Apparatus for mixing and treating fluids

ABSTRACT

An apparatus for mixing and treating fluids includes a rotatable hollow shaft having an impeller section which is extended into a first fluid. The impeller section includes a plurality of spiral blades which move and agitate the first fluid and an opening adjacent the blades through which a second fluid in the shaft communicates with the first fluid. The movement of the first fluid creates a suction zone which causes the second fluid to be drawn through the shaft and out the opening.

UnIted States Patent 1191 1111 3,782,702 King 1 Jan. 1, 1974 [5 1APPARATUS FOR MIXING AND TREATING 3,252,690 5/1966 Martin 259 96 xFLUIDS 1,757,197 5/1930 Johnson.... 259/96 R b S 7100 P P] 3,490,9961/1970 Kelly, 11' 261/87 ux [76] Inventor fi gt k 'f ampa FOREIGNPATENTS OR APPLICATIONS 879,861 12/1942 Germany 209/169 1 1 Ffledl 29,1969 518,854 3/1940 Great Britain... 259/96 862,761 3/1961 GreatBritain... 210/197 [21] Appl' 888787 98,086 2/1940 Sweden 209/169 [52]US. Cl. 261/87, 209/169 [51] Int. Cl B011 3/04 [58] Field of Search261/93, 91, 87, 84, 261/28, 29; 259/96, 95, 97; 210/208, 194, 199,14,15, 220, 221; 209/168-170 [56] References Cited UNITED STATES PATENTS1,242,445 10/1917 lttner 261/87 1,901,123 3/1933 Ruth, Jr. 209/169 X1,902,078 3/1933 Jenks 210/197 X 1,949,696 3/1934 Schoneb0rn.. 259/962,072,944 3/1937 Durdin 261/91 UX 2,170,496 8/1939 Gard et a1 261/932,448,590 9/1948 Gunther 261/87 2,996,287 8/1961 Audran 261/87 X PrimaryExaminer-Robert Halper Attorney Lyon and Lyon [57] ABSTRACT An apparatusfor mixing and treating fluids includes a rotatable hollow shaft havingan impeller section which is extended into a first fluid. The impellersection includes a plurality of spiral blades which move and agitate thefirst fluid and an opening adjacent the blades through which a secondfluid in the shaft communicates with the first fluid. The movement ofthe first fluid creates a suction zone which causes the second fluid tobe drawn through the shaft and out the opening.

12 Claims, 6 Drawing Figures APPARATUS FOR MIXING AND TREATING FLUIDSThis invention relates to the mixing and treating of fluids and isparticularly directed to the distribution of one fluid into another bythe use of a rotary member having a novel impeller section whichcontributes to the efficient mixing and treating of the fluid.

The mixing of two or more fluids can be accomplished in several ways.The most common is to add the two or more masses of fluidsto the samevessel and agitate to disperse one or more of the fluids into the other.This method has been effective in the preparation of certain mixturesbut other means are usually necessary when the fluids to be mixed havesubstantially different specific gravities, as in the case when it isdesired to mix a gas such as air with a liquid such as water. This isparticularly the case when it is desirable to mix and disperse the gaswith the liquid at a depth substantially below the surface of theliquid. The mixture or treatment of air and water, generally referred toas aeration, is particularly desirable in the treatment of pollutedwater or sewage. It has been found that the aeration of the sewagepromotes the growth of aerobic bacteria, which in turn converts thewaste material to carbon dioxide and biological sludge. Normally, theaeration of sewage is accomplished by spraying the polluted water intothe surrounding air. However, this method has proved only partiallysuccessful because it effectively produced bacterial action only a fewfeet below the surface of the polluted water.

Therefore, it is a primary object of this invention to provide a meansfor rapidly dispersing and mixing at least one fluid into a mass ofanother fluid which is effective when mixing two fluids havingsubstantially different specific gravities.

Another object of this invention is to mix two fluids havingsubstantially different specific gravities by dispersing the fluidhaving the lighter specific gravity substantially below the surface ofthe fluid having the heavier specific gravity. 4

In accomplishing this and other objects, the invention includes arotatable member having a hollow shaft and an impeller section. Theshaft is adapted to extend into a first fluid and communicate a secondfluid from above the surface of the first fluid to an opening adjacentspiral blades on theimpeller section. The blades are adapted to move andagitate the first fluid and thereby create a suction zone at the openinginto which the second fluid is drawn from the shaft.

Another object of this invention is to provide an apparatus which isnon-clogging during the mixing of a fluid containing solids.

A still further object of this invention is to provide a means fordispersing a gas substantially below the surface of a liquid topressurize the gas.

Other and further objects and advantages of this invention will be madereadily apparent from the accompanying drawings and followingdescription.

In the drawings:

FIG. 1 is a side view of the mixing and dispersing apparatus extendedsubstantially below the surface of a fluid.

FIG. 2 is a side view illustrating the impeller section.

FIG. 3 is a cross-sectional side view of the impeller section takensubstantially on the lines 3-3 of FIG. 2.

FIG. 4 is a fragmentary view illustrating an alternative embodiment ofthe impeller section.

FIG. 5 is a fragmentary view illustrating another alternative embodimentof the impeller section.

FIG. 6 is a side view illustrating the mixing and dispersing apparatusin a compressor system.

Referring now in detail to the drawings, the mixing and dispersingapparatus, generally designated 10, as shown in FIG. 1 includes a hollowshaft 11 with an integral impeller section, generally designated 12, atits lower end. A squirrel cage motor 13 adapted to rotate the shaft 11and impeller section 12 is connected to a universal joint 14 which is inturn connected to the upper end of the shaft 11. The shaft 11, as seenin FIGS. 2 and 3, is hollow and is adapted to extend substantially belowthe surface of a first fluid 15 from a second fluid 16 above the surfaceof the first fluid 15. An opening 16a is provided at the upper end ofthe shaft 11 for communication of the second fluid 16 into the hollowshaft 11. The opening 16a is positioned above the surface of the firstflpid 15, but the exact position of the opening 16a and the size thereofmay vary. Moreover, it may be desirable in certain instances to providemore than one opening 16a.

The impeller section includes a downwardly extending surface 17 and anupwardly extending surface 18. The downwardly extending surface 17 iscurved in cross-section and begins on the shaft 11 parallel to the axisof the shaft and curves downward and outward and terminates in aradially extending flange 19 which in the preferred embodiment is normalto the axis of the shaft 11. The upwardly extending flared surface 18 iscurved in cross-section and begins at the lower end of the shaft 11 andcurves upward and outward and terminates in the preferred embodiment ina radially extending flange 20, which in the preferred embodiment isnormal to the axis of the shaft 11. The surfaces 17 and 18 each includea plurality of continuous spiral screw blades 21 which encircle thecurved surfaces 17 and 18. The outer periphery of the blades 21 on thesurface 17 defines a flaring surface of revolution 17a. The outerperiphery of the blades 21 on the surface 18 defines a flaring surfaceof revolution 18a. The blades 21 are all of substantially constantthickness and the blades 21 on surface 17 merge at one end 22 with theshaft 11 and terminate at the other end 23 on the flange 19. The blades21 on surface 18 merge at one end 22a at the hub 21a of the impellersection and terminate at the other end 2311 on the flange 20. Moreover,as illustrated in FIGS. 2 through 5, the blades 21 as they extend fromthe ends 22 and 22a are inclined with respect to the axis of the shaft11.

A circumferential outlet or opening 24 positioned adjacent the radiallyoutmost extension of the ends 23 and 23a of the blades 21 and betweenthe surfaces of revolution 17a and 18a is provided for communication ofthe second fluid 16 in the hollow shaft with the first fluid 15. Withinthe interior chamber 25 of the impeller section 12 are spaced vanes 26which extend radially inward normal to the axis of the shaft 11 from theoutlet 24) The vanes 26 direct the second fluid 16 from within the shaft11 and assist in distributing the second fluid 16 in the first fluid 15.

In operation the shaft 11 and impeller section 12 are rotated by themotor 13 opposite the direction which the blades 21 encircle thesurfaces 17 and 18 when beginning at the ends 22 and 22a. The rotationof the impeller section 12 causes the blades 21 to move the first fluid15 along two continuous generally vertical paths above and below theopening 24 downward along the shaft and the surface 17 and axiallyupward along the surface 18 and then radially outward as indicated bythe directional arrows in FIGS. 2 and 3. It should be noted that thefirst fluid 15 is moved by the blades 21 in a clockwise direction alongone path and in a counter-clockwise direction along the other path. Themovement of the first fluid l5 creates a vacuum or suction zone betweenthe two paths of movement and immediately opposite the circumferentialopening 24 and the vacuum Zone causes the second fluid 16 to be drawnthrough the hollow shaft 11 and out the circumferential opening 24between the vanes 26 into the first fluid 15.

In the alternate embodiment shown in FIG. 4 the impeller section 12 isidentical except the flange 30. on the surface 17 extends radiallyoutward and is inclined downwardly on an incline which is complimentaryto the incline of the flange 31 on the surface 18. This embodiment isadapted to direct the second fluid l6 radially outward and downward intothe first fluid 15 as shown by the directional arrows in FIG. 4.

In the alternate embodiment shown in FIG. 5 the impeller section 12 isidentical except the flanges 40 and 41 on the surfaces 17 and 18,respectively, are flared to increase the size of the circumferentialopening 42 and thereby increase the amount of the flow of the secondfluid 16 into the first fluid 15.

Other modifications within the scope of the invention which although notshown, should be evident from the discussion of the invention. One ofthese modifications includes an impeller section 12 having only an uppersurface 17a with a flat horizontal surface below the circumferentialopening 24 instead of the curved surface 18 with the blades 21. In thismodification substantially only the fluid 15 above the opening 24 ismoved radially outward adjacent the opening 24. Another modificationincludes an impeller section having only a lower surface of revolution18 with the shaft 11 terminating above the circumferential opening ontoa flat horizontal surface which extends radially outward from the shaft11. In this modification substantially only the fluid 15 below thecircumferential opening is moved radially outward adjacent the opening24. It should be further evident that these latter two modifications canbe further modified by changing the flanges adjacent the opening 24 inthe manner shown in FIGS. 4 and 5.

Besides moving the fluid 15 the blades 21 during rotation act todisintegrate solids in the first fluid 15 which contact the impellersection 12. Furthermore, the design of the impeller section 12 is suchthat it is non-clogging when the first fluid 15 contains solids and thedesign of the blades 21 and the surfaces of revolution 17 and 18 aresuch that the directional transition of the fluid 15 is smooth and theacceleration of the fluid 15 along the surfaces of revolution 17 and 18is uniform thereby providing an apparatus which is efficient inoperation. Moreover, while the device is particularly effective in themixing and dispersing of air with polluted water substantially below thesurface of the water, the device can also be for various other purposes.The device 10 may be used as an evaporative cooler when there isrelatively shallow submergence of the impeller section 12 and in acompressor unit when the impeller section 12 is deeply submerged in afluid having relatively heavy specific gravity with respect to the gasbeing compressed. Use of the device 10 in a compressor unit is shown inFIG. 6.

The compressor unit, generally designated 50, includes a plurality ofthree tanks 51, 52 and 53 containing a liquid 54. Tank 51 is open to theatmosphere at the top and the shaft 11 of the device 10 is extendedbelow the surface 55 of the liquid 54. The motor 13 and the openings forcommunication of air into the hollow shaft 11 are located above thesurface 55. The depth which the impeller section 12 is submerged dependson the static head h necessary to compress the gas or air beingdispersed into the fluid 54.

Adjacent the circumferential opening 24 of the impeller section 12 is anair directing member 57 and baffles 58. The air directing member 57 isgenerally cylindrical with the walls extending vertically. The airdirecting member 57 is adapted to direct the air bubbles which are mixedinto the liquid 54 by the device 10 up into a chamber 59 of an invertedcontainer 60 which includes a central cylindrical opening 61 whichsurrounds the shaft 11. The baffles 58 are generally flat plates whichextend radially with respect to the axis of the shaft 11. Additionalbaffles 62 are secured to the walls of the tanks 51, 52 and 53 below thecontainers 60 and also extend radially with respect to the axis of theshaft. The baffles 58 and 62 are adapted to break up the circumferentialflow of the liquid 54 in the tanks 51, 52 and 53 during rotation of theimpeller sections 12.

Tank 52 is enclosed at its upper end by a cover 63. The cover 63 and thewalls of the tank 52 define a pressure chamber 64. The motor 13 islocated outside the pressure chamber 64 and above the cover 63. Sealmeans 65 provide an air tight seal between the cover 63 and the shaft 66which operably connects the motor 13 to the rotatable shaft 11.

A conduit 67 connected at one end 68 to the container 60 in tank 51 andconnected at the other end 69 to the tank 52 is adapted to communicatethe pressurized air from the chamber 59 in tank 51 to the pressurechamber 64 in tank 52. A valve 70 controls the flow of air into pressurechamber 64 and also prevents the return of any air from the pressurechamber 64 to the chamber 59 in tank 51. Control means 70a controls theopening and closing of the valve 70.

Tank 53 is also enclosed at its upper end by a cover 71 which along withthe walls of the tank 53 also defines a pressure chamber 72. Seal means73 provide an air tight seal between the cover 71 and the shaft 74operably connecting the motor 13 with shaft 11. A conduit 75 connectedat one end 76 to the container 60 in tank 52 and connected at the otherend 77 to the tank 53 is adapted to communicate pressurized air from thechamber 59 in tank 52 to the pressure chamber 72 in tank 53. A valve 78controls the flow of air into pressure chamber 72 and also prevents airfrom returning to the chamber 59 in the tank 52. Control means 79controls the opening and closing of the valve 78.

Another conduit 80 connected at one end 81 to the container 60 in thetank 53 is adapted to communicate the pressurized air from the tank 53.

The compressor unit 50 operates by drawing air under atmosphericpressure into and through the hollow shaft to the impeller section 12which is submerged below the surface 55 of the liquid 54. The air isdrawn through the shaft and out through the circumferential opening 24into the liquid 54 by the rotation of the impeller section 12 which asdescribed above creates a vacuum zone adjacent the opening 24. The airis dispersed in the liquid 54 in the form of bubbles and the bubbles aredirected and guided by the air directing member 57 into the chamber 59in the tank 51. The pressure of the air in the chamber 59 in the tank 51is dependent on the static head h of the liquid which is acting on theair in the chamber 59in the tank 51. This pressurized air iscommunicated to the pressure chamber 64 where it is drawn throughopenings in the upper end of the shaft 11 of the device in the tank 52through the shaft 11 into the vacuum zone adjacent the opening 24created by the action of the impeller section 12 in the tank 52. Thispressurized air from the Y chamber 64 is further pressurized by theliquid acting on the air collected in the chamber 59 in the tank 52. Thefurther pressurized air is communicated through the conduit 75 to thepressure chamber 72. The air in the pressure chamber 72 is thendispersed into the fluid 54 in the tank 53 by the device 10 in the tank53 and is again further pressurized by the liquid 54 acting on the aircollected in the chamber 59 in the tank 53. The pressure of this airwhich is communicated from the tank 53 by the conduit 80 has a pressurewhich is generally equal to atmospheric pressure plus the static head h"of all three tanks 51, 52 and 53 times the specific weight of liquid 54.It should be noted that additional tanks and additional mixing anddispersing devices can be provided to further increase the pressure ofthe air.

The use of this device 10 in a compressor unit provides a compressorunit which is free from oil contamination and which can operate withoutan aftercooler. Having fully described my invention, it is to beunderstood that I do not wish to be limited to the details set forth,but my invention is of the full scope of the appended claims.

l claim:

I. An apparatus for mixing and dispersing a first fluid into a secondfluid, comprising: a shaft;

an impeller section on said shaft adapted to be submerged and rotated ina first fluid, said impeller section including first and second externalsurfaces and an internal chamber within said first and second externalsurfaces;

means including a passageway in communication with a second fluid andextending from said second fluid to said internal chamber forcommunication of said second fluid to said internal chamber;

said first external surface being curved in crosssection and having aflange portion extending radially from the axis of said shaft;

a plurality of continuous spiral screw blades encircling said firstexternal surface and terminating on said flange portion, said bladeshaving an outer periphery defining a flaring surface of revolution andadapted to circulate said first fluid along said first external surfaceand radially outward past said flange portion; and

said impeller section having an opening between said first and secondexternal surfaces and adjacent to said flange portion, said opening incommunication with said internal chamber and adapted to pass said secondfluid from said internal chamber into said first fluid.

2. The apparatus of claim 1, wherein said second external surface iscurved in cross-section and has a flange portion extending radially fromthe axis of said shaft and adjacent said opening, a plurality ofcontinuous spiral screw blades encircling said second external surfaceand terminating on said flange portion, said blades having an outerperiphery defining a flaring surface of revolution and adapted to movesaid first fluid along said second external surface and radially outwardpast said flange portion.

3. The apparatus of claim 2, wherein a plurality of five spiral screwblades encircle said first external surface and a plurality of fivespiral screw blades encircle said second external surface.

4. The apparatus of claim 1, wherein said second external surface has aflange adjacent said opening and said flanges of said first and secondexternal surfaces extend outwardly and downwardly.

5. The apparatus of claim 1, wherein said second external surface has aflange adjacent said opening, and said flanges of said first and secondexternal surfaces are flared.

6. The apparatus of claim 1, wherein said opening extendscircumferentially around said impeller section.

7. The apparatus of claim 6, wherein vanes are provided in said internalchamber, said vanes extending radially inward from said circumferentialopening to said internal chamber and adapted to direct said second fluidfrom said internal chamber through said circumferential opening.

8. The apparatus of claim 1, wherein said first external surface iscurved in cross-section downwardly and outwardly and said secondexternal surface is curved in cross-section upwardly and outwardly, saidsecond surface having a radially extending flange portion, and aplurality of continuous spiral screw blades encircling said secondexternal surface and having a periphery defining a flaring surface ofrevolution.

9. The apparatus of claim 8, wherein said blades on said first externalsurface downwardly encircle said first external surface in the samedirection in which said blades upwardly encircle said second externalsurface.-

10. An apparatus for mixing and dispersing a first fluid into a secondfluid, comprising: a shaft;

an impeller section on said shaft adapted to be submerged and rotated ina first fluid, said impeller section including first and second externalsurfaces and an internal chamber within said first and second externalsurfaces;

means including a passageway in communication with a second fluid andextending from said second fluid to said internal chamber forcommunication of said second fluid to said internal chamber;

said first and second external surfaces each being curved incross-section and each having a flange portion extending radially fromthe axis of said shaft;

a plurality of continuous spiral screw blades encircling said first andsecond external surfaces and extending from a section on said surfacessubstantially in axial alignment with said shaft toward said flangeportions, said blades smoothly transforming the movement of direction ofsaid first fluid from an axial direction substantially to a radialdirection past said flange portions during rotation of said impellersection;

dially inward from said circumferential opening to said internalchamber.

12. The apparatus of claim 10 wherein said spiral screw bladesencircling said external surfaces are inclined with respect to the axisof said shaft as they extend toward said flange portions.

1. An apparatus for mixing and dispersing a first fluid into a secondfluid, comprising: a shaft; an impeller section on said shaft adapted tobe submerged and rotated in a first fluid, said impeller sectionincluding first and second external surfaces and an internal chamberwithin said first and second external surfaces; means including apassageway in communication with a second fluid and extending from saidsecond fluid to said internal chamber for communication of said secondfluid to said internal chamber; said first external surface being curvedin cross-section and having a flange portion extending radially from theaxis of said shaft; a plurality of continuous spiral screw bladesencircling said first external surface and terminating on said flangeportion, said blades having an outer periphery defining a flaringsurface of revolution and adapted to circulate said first fluid alongsaid first external surface and radially outward past said flangeportion; and said impeller section having an opening between said firstand second external surfaces and adjacent to said flange portion, saidopening in communication with said internal chamber and adapted to passsaid second fluid from said internal chamber into said first fluid. 2.The apparatus of claim 1, wherein said second external surface is curvedin cross-section and has a flange portion extending radially from theaxis of said shaft and adjacent said opening, a plurality of continuousspiral screw blades encircling said second external surface andterminating on said flange portion, said blades having an outerperiphery defining a flaring surface of revolution and adapted to movesaid first fluid along said second external surface and radially outwardpast said flange portion.
 3. The apparatus of claim 2, wherein aplurality of five spiral screw blades encircle said first externalsurface and a plurality of five spiral screw blades encircle said secondexternal surface.
 4. The apparatus of claim 1, wherein said secondexternal surface has a flange adjacent said opening and said flanges ofsaid first and second external surfaces extend outwardly and downwardly.5. The apparatus of claim 1, wherein said second external surface has aflange adjacent said opening, and said flanges of said first and secondexternal surfaces are flared.
 6. The apparatus of claim 1, wherein saidopening extends circumferentially around said impeller section.
 7. Theapparatus of claim 6, wherein vanes are provided in said internalchamber, said vanes extending radially inward from said circumferentialopening to said internal chamber and adapted to direct said second fluiDfrom said internal chamber through said circumferential opening.
 8. Theapparatus of claim 1, wherein said first external surface is curved incross-section downwardly and outwardly and said second external surfaceis curved in cross-section upwardly and outwardly, said second surfacehaving a radially extending flange portion, and a plurality ofcontinuous spiral screw blades encircling said second external surfaceand having a periphery defining a flaring surface of revolution.
 9. Theapparatus of claim 8, wherein said blades on said first external surfacedownwardly encircle said first external surface in the same direction inwhich said blades upwardly encircle said second external surface.
 10. Anapparatus for mixing and dispersing a first fluid into a second fluid,comprising: a shaft; an impeller section on said shaft adapted to besubmerged and rotated in a first fluid, said impeller section includingfirst and second external surfaces and an internal chamber within saidfirst and second external surfaces; means including a passageway incommunication with a second fluid and extending from said second fluidto said internal chamber for communication of said second fluid to saidinternal chamber; said first and second external surfaces each beingcurved in cross-section and each having a flange portion extendingradially from the axis of said shaft; a plurality of continuous spiralscrew blades encircling said first and second external surfaces andextending from a section on said surfaces substantially in axialalignment with said shaft toward said flange portions, said bladessmoothly transforming the movement of direction of said first fluid froman axial direction substantially to a radial direction past said flangeportions during rotation of said impeller section; and said impellersection having a circumferential opening positioned between said firstand second external surfaces adjacent to said flange portions, saidopening in communication with said internal chamber and adapted to passsaid second fluid from said internal chamber into said first fluid. 11.The apparatus of claim 10 wherein vanes are provided in said internalchamber, said vanes extending radially inward from said circumferentialopening to said internal chamber.
 12. The apparatus of claim 10 whereinsaid spiral screw blades encircling said external surfaces are inclinedwith respect to the axis of said shaft as they extend toward said flangeportions.